Abstract:

BACKGROUND: Progress in the gene therapy of β-thalassemia would not have been possible without the development of suitable animal models of the disease. Mouse models are the most useful and are generally adopted as first line in vivo studies.
OBJECTIVE: To generate humanized β-thalassemia mice models, and to provide the similar reliable humanized animal models towards the genetic treatment of β-thalassemia.
METHODS: Totally 15 nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice were randomly divided into three groups: β- thalassemia/HbE bone marrow transplantation group, β-thalassemia bone marrow transplantation group and blank control group. The bone marrow mononuclear cells of β-thalassemia/HbE and β-thalassemia patients were transplanted into the sublethally irradiated (⁶⁰Coγ ray 350cGy) NOD/SCID mice of the transplantation group by tail vein injection. RPMI-1640 medium was infused into blank control group. After transplantation, human recombinant growth factors consisting of recombinant human erythropoietin (rhEPO) and recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) were injected into the mice intraperitoneally. The survival status of the mice was recorded. Five weeks after transplantation, bone marrow and peripheral blood were collected to detect human CD45⁺cell proportion, β-thalassemia gene, to observe α-globin chain precipitates in erythroid cells.The spleen and liver were observed, and iron staining was performed.
RESULTS AND CONCLUSION: Five weeks after transplantation, the percentages of human CD45⁺ cells of the β-thalassemia/HbE bone marrow transplantation group in bone marrow and peripheral blood were 7.21% and 4.08% in +47 day, 7.37% and 6.03% in +61 day, respectively; those of the β-thalassemia bone marrow transplantation group were 8.17% and 3.43% in +36 day, 16.82% and 8.89% in +45 day, respectively. While in blank control group, the percentage of that of each mouse was 0, respectively. The results of β-thalassemia gene mutations corresponded with the donor. There were α-globin chain precipitates in some erythroid cells. The ratios of the spleen length to body weight of the transplantation group were greater than those of blank control group (P < 0.05). The iron deposition was observed in liver and spleen of mice from the transplantation group. Results suggest that there are humanized cell and β-thalassemia features in the mice of β-thalassemia or β-thalassemia/HbE bone marrow transplantation group, and humanized β-thalassemia mice models are generated successfully.